The proposed research concerns the follow-up of males initially seen in mental health clinics in 1987, mostly for disruptive behavior disorders at ages 7 to 12. Since that time the participants have been regularly assessed to document the course and outcome of disruptive behavior disorders. The latest assessments were at ages 18 and 19, with the aim of documenting antisocial personality disorder and the infliction of harm. Currently, 36 percent qualify for the diagnosis of antisocial personality disorder. Forty five percent have inflicted moderate to serious injury on other individuals, and 24 percent have attempted suicide. Because violence usually increases during early adulthood, and because the stability of antisocial personality disorder over time is modest, the project proposes to follow up the participants at age 24.The aims of the proposed research are to test and extend a life-span developmental model of the origins of adult antisocial personality disorder and harm infliction using data on potential risk factors measured from childhood into early adulthood, and to document the relationship between antisocial personality disorder, psychopathy, other personality disorders, and personality traits to identify those individuals who are most at risk to inflict harm and to improve understanding of the adult outcomes of chronic conduct disorder.